Vipera russelli siamensis

Daboia siamensis (Common name: Eastern Russell's viper, Siamese Russell's viper, more) is a venomous viper species that is endemic to parts of Southeast Asia, southern China and Taiwan. It was formerly considered to be a subspecies of Daboia russelii (as Daboia russelli siamensis), but was elevated to species status in 2007. Dorsally, the color pattern is the same as that of D. russelii, except that the color is more grayish or olive, with small spots between the large spot rows. The venter is suffused with gray posteriorly. Eastern Russell's viper, Siamese Russell's viper. Previously, other common names were used to describe subspecies that are now part of the synonymy of this form: Indonesian Russell's viper for 'limitis', and Formosan Russell's viper for 'formosensis'. D. siamensis is found in Myanmar, Thailand, Cambodia, China (Guangxi, Guangdong), Taiwan and Indonesia (Endeh, Flores, east Java, Komodo, Lomblen Islands). Brown (1973) mentions that D. siamensis can also found in Vietnam, Laos and on the Indonesian island of Sumatra. Ditmars (1937) reportedly received a specimen from Sumatra as well. However, its distribution in the Indonesian archipelago is still being elucidated. A monovalent antivenin, called 'Russell's Viper Antivenin', is made in Thailand by the Thai Red Cross to counteract the venom of this species.